JP2004164547A - Electronic equipment with communication function - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To ensure communication without any influence by a metallic box. <P>SOLUTION: The electronic equipment comprises a metallic box 122 which houses electric parts, and a communication antenna part 90 which is arranged in the box 122 and makes communication with an IC card 110 having an antenna part 115 built-in and having communication function. The communication antenna part 90 is arranged in the box 122 at such a position that, when the IC card 110 approaches the box 122, a part of the antenna part 115 built in the IC card 110 overlaps with a part of the communication antenna part 90 and a part of the antenna part 115 on the side of the IC card 110 does not overlap with the box 122, thereby suppressing the reduction in inductance of the antenna part 115 on the IC card 110 side. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an electronic device having a communication function of writing and reading data to and from a non-contact type IC card that inductively couples an electromagnetic field.
[0002]
[Prior art]
In recent years, so-called RFID (Radio Frequency IDentification) systems using non-contact IC cards and IC tags have been introduced in fields such as railway automatic ticket gates, security systems for entering and exiting buildings, and electronic money systems. Has begun to be. This RFID system, as schematically shown in FIG. 1, includes a non-contact type IC card 100 and a reader / writer 101 which writes and reads data to and from the IC card 100. In this RF system, based on the principle of electromagnetic induction, when a magnetic flux is radiated from the loop antenna 102 on the reader / writer 101 side, the radiated magnetic flux is magnetically coupled to the loop antenna 103 on the IC card 100 side by inductive coupling. Then, communication is performed between the IC card 100 and the reader / writer 101.
[0003]
In such an RFID system, unlike a conventional contact type IC card system, it is not necessary to load an IC card on a reader / writer or contact a metal contact, and data can be written and read easily and at high speed. It can be carried out.
[0004]
In this RFID system, necessary power is supplied from the reader / writer 101 to the IC card 100 by electromagnetic induction. Therefore, there is no need to provide a power source such as a battery in the IC card, and the configuration can be simplified and the price can be reduced. A highly reliable IC card can be provided.
[0005]
In the above-described RFID system, in order to secure a sufficient communication range between the IC card 100 and the reader / writer 101, a loop antenna 102 capable of radiating an electromagnetic field having a certain magnetic field strength is provided on the reader / writer 101 side. Must be provided.
[0006]
In general, the loop antenna 102 for the reader / writer 101 is composed of a loop coil 200 in which a conducting wire is wound in a planar shape as shown in FIG. 2, and the loop coil 200 faces each other with a center portion thereof interposed therebetween. It has a symmetrical shape with equal spacing and line width between each winding. In addition, as these specific examples, the main body side antenna 90 connected to the Reader / Writer module 91 (for example, refer to Patent Document 1) and the AG1, AG2, and AG3 of the read / write device RW2 (for example, Patent Document 2) And the like.).
[0007]
Accordingly, the loop antenna 102 for the reader / writer 101 having such a symmetric shape has a symmetric magnetic field distribution as shown in FIG.
[0008]
FIG. 4 shows the card position dependence of the current intensity induced in the IC card 100 by the loop antenna 102. The two communicable areas S1 ', S2 'will be formed. Specifically, the communicable region S1 'is an ideal region where the magnetic fields generated from the four opposing sides of the loop antenna 102 on the reader / writer 101 side and the loop antenna 103 on the IC card 100 side are inductively coupled at their respective positions. In contrast to this, when the communication area is outside the communicable area S1 ', the loop area on the IC card 100 side in the central area where the direction of the magnetic field generated by the loop antenna 102 on the reader / writer 101 side is reversed. Since the magnetic fields intersecting with the antenna 103 cancel each other, the induced current becomes lower than the level required for communication. Further, when going outward, only one of the four sides of the loop antenna 102 on the reader / writer 101 side and the loop antenna 103 on the IC card 100 side is coupled to each other. A small and narrow communicable area S2 'appears.
[0009]
In FIG. 4, the origin 0 on the horizontal axis indicates the center position of the loop antenna 102 on the reader / writer 101 side, and the positive direction indicates the direction in which the IC card 100 faces outward from the origin 0. On the other hand, the vertical axis indicates the induced current intensity generated by the magnetic field of the loop antenna 102 on the reader / writer 101 side by the electromagnetic induction in the loop antenna 103 on the IC card 100 side, and is equal to or more than the value indicated by a dotted line s ′ in FIG. The area becomes a communicable area.
[0010]
Here, when the center position of the loop antenna 103 on the IC card 100 side matches that of the loop antenna 102 on the reader / writer 101 side, that is, as the communicable area S1 'continuously and greatly widens from the origin 0, the usability increases. Will be good.
[0011]
In the above-described conventional loop coil 200, when going outward from the origin 0, it temporarily deviates from the communicable area S1 'to enter a non-communicable area, and moves further outward to reenter the communicable area S2'. Will be. From a practical point of view, it is desirable that there be no non-communicable area between the communicable area S1 'and the communicable area S2', in other words, only the communicable area S1 'be expanded.
[0012]
Such a loop antenna 102 for the reader / writer 101 cannot be used by being directly attached to a metal case made of a Mg alloy or the like due to the influence of eddy current or the like. For this reason, as shown in FIG. 5, when a metal casing 300 is used, a magnetic sheet 301 is interposed between the casing 300 and the loop coil 200, and protection is provided on the loop coil 200. The structure is such that a resin sheet 302 made of a material such as polycarbonate is arranged. Also in this case, the loop antenna 102 for the reader / writer 101 cannot efficiently radiate an electromagnetic field to the IC card 100, and the communicable range between the IC card 100 and the reader / writer 101 becomes narrow. Problems arise.
[0013]
When the housing 400 is made of a synthetic resin, as shown in FIG. 6, the electric circuit board 401 and the loop antenna 102 in the synthetic resin housing 400 are used to prevent electromagnetic induction noise from being generated in the electronic circuit. It is necessary to arrange the spacer 402 between them, and the thickness increases. The loop antenna 102 for the conventional reader / writer 101 has substantially the same size as the loop antenna 103 on the IC card 100 side. With such a conventional loop antenna 102 for the reader / writer 101, it is difficult to reduce the size and thickness.
[0014]
While there are technical difficulties as described above, for example, the above-described reader / writer 101 may be mounted on a synthetic resin housing or a metal housing constituting a portable small electronic device. . In this case, a loop antenna 102 for a reader / writer that is equal to or smaller than the outer shape of the IC card 100 and is thin is required.
[0015]
The portable small electronic device described above is different from the fixedly mounted electronic device in that the size of the device is limited, and therefore, even if the arrangement space is devised, the electromagnetic field radiated by the loop antenna 102 will be inside. In order to reduce the influence on the electronic circuit board and the like disposed close to each other and to reduce the influence on the loop antenna 102 by the metal housing, there is a great restriction in securing the internal space. . Therefore, a new method for reducing the influence of the metal casing on the loop antenna 102 and the influence of the electromagnetic field radiated by the loop antenna 102 itself on the electronic circuit board and the like are desired.
[0016]
Further, portable small electronic devices are strongly demanded for low power consumption, cannot afford to increase the drive current of the loop antenna 102, and have a high efficiency that can secure a sufficient magnetic field strength even with a small drive current. A new antenna structure is required.
[0017]
Still further, a portable electronic device may not always have a desired R / W 101 transmission / reception position due to a loop antenna, depending on the installation location restrictions and the positional relationship with a location for performing other functions such as a keyboard constituting an operation unit. There is also a unique request for a small portable electronic device that does not become the center of the device 102 and that it is desired to freely set the transmitting / receiving position in consideration of usability.
[0018]
By the way, as a conventional technique capable of reducing the influence of the metal housing on the loop antenna 102 by a method other than the spatial arrangement, an IC tag antenna using a plate-shaped magnetic material to reduce the influence of a metal body (for example, see Patent Document 1) 3), and a card loader antenna using a magnetic material to deflect the antenna magnetic field to reduce the influence of a metal body (see, for example, Patent Document 4).
[0019]
[Patent Document 1]
JP-A-10-144048 (page 3-4, FIG. 4)
[Patent Document 2]
JP-A-2001-331829 (page 19, FIG. 16)
[Patent Document 3]
JP 2001-331772 A
[Patent Document 4]
JP-A-2002-123799
[0020]
[Problems to be solved by the invention]
The above-described conventional technologies realize an optimal small and thin R / W loop antenna for a portable small electronic device in which power consumption and installation place are materially and spatially limited. Is difficult.
[0021]
An object of the present invention is to provide a new electronic device with a communication function that can solve the problems of the conventional technology as described above.
[0022]
Another object of the present invention is to provide an electronic device with a communication function that enables accurate transmission and reception of write and / or read information by reducing the influence of a material forming a housing that forms a device main body. It is in.
[0023]
Still another object of the present invention is to provide an electronic device with a communication function that enables further miniaturization and higher performance of the device itself.
[0024]
[Means for Solving the Problems]
In order to achieve the above-described object, an electronic device with a communication function according to the present invention includes a metal housing for housing components and a communication function that is disposed in the housing and includes a loop antenna. A communication antenna unit for communicating with the IC card, wherein the communication antenna unit is configured such that when the IC card approaches the housing, a part of the antenna unit built in the IC card becomes part of the communication antenna unit. The antenna is disposed on the housing such that the antenna overlaps and a part of the antenna portion on the IC card side does not overlap with the housing. Here, a loop antenna composed of a loop coil is used for the antenna unit on the IC card side.
[0025]
The metal housing has at least a communication antenna unit disposed therein and a width of an area where a part of the IC card is opposed to the IC card, which has a rectangular shape having at least a short side and a long side. It is smaller than the length in the long side direction.
[0026]
The metal housing of the electronic device according to the present invention is provided with an index portion that indicates the position of the antenna portion provided in the housing.
[0027]
In a region of the metal housing facing the IC card, a positioning portion for positioning a position facing the housing of the IC card is provided.
[0028]
The electronic device according to the present invention, when an IC card having a communication function with a built-in antenna is approached to a metal case, that is, when the IC card is positioned on the case, the Only a part thereof overlaps with a part of the communication antenna portion on the housing side, thereby preventing deterioration of communication characteristics for transmitting / receiving information to / from the IC card.
[0029]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an electronic device with a communication function according to the present invention will be described with reference to the drawings.
[0030]
First, an antenna device used in an electronic device with a communication function according to the present invention will be described. This antenna device is used in an RFID system having a configuration as shown in FIG. As shown in FIG. 7, the RFID system includes a non-contact type IC card 1 and a reader / writer (hereinafter, referred to as R / W) 50 for writing and reading data to and from the IC card 1. I have.
[0031]
The IC card 1 is a so-called batteryless IC card which does not include a power supply such as a battery compliant with ISO7810. This IC card is formed in a rectangular shape having the short side and the long side of the same size as a so-called credit card, that is, a size that can be put on a palm. In the IC card 1, a loop antenna 2 for transmitting and receiving data in combination with an electromagnetic field, an electronic circuit and a memory for performing various processes for writing and reading data are integrated on a substrate provided therein. IC (Integrated Circuit) 3.
[0032]
The loop antenna 2 includes a loop coil 4 in which a conductive wire is wound in a plane, and forms a resonance circuit together with a capacitor 5 connected in parallel with the loop coil 4. The loop antenna 2 is coupled to an electromagnetic field radiated from a loop antenna on the R / W 50 side, which will be described later, converts the coupled electromagnetic field into an electric signal, and supplies the electric signal to the IC.
[0033]
The IC 3 includes a rectifier circuit 6 that rectifies and smoothes the electric signal supplied from the loop coil 4, a regulator 7 that converts the electric signal supplied from the rectifier circuit 6 into DC power, and a rectifier circuit 6 that converts the electric signal supplied from the rectifier circuit 6. An HPF (High Pass-Filter) 8 for extracting a high frequency component, a demodulation circuit 9 for demodulating a high frequency component signal input from the HPF 8, and data writing and data corresponding to the data supplied from the demodulation circuit 9. It includes a sequencer 10 for controlling reading, a memory 11 for storing data supplied from the demodulation circuit 9, and a modulation circuit 12 for modulating data transmitted by the loop coil 4.
[0034]
The rectifier circuit 6 includes a diode 13, a resistor 14, and a capacitor 15. The anode terminal of the diode 13 is connected to one end of the loop coil 4 and one end of the capacitor 5, the cathode terminal of the diode 13 is connected to one end of the resistor 14 and one end of the capacitor 15, and the other end of the resistor 14 and the capacitor 15 are connected to the loop coil 4. And the other end of the capacitor 5. The rectifier circuit 6 outputs an electric signal obtained by rectifying and smoothing the electric signal supplied from the loop coil 4 to the regulator 7 and the HPF 8.
[0035]
The regulator 7 is connected to the cathode terminal of the diode 13 of the rectifier circuit 6, the resistor 14, and one end of the capacitor 15. The regulator 7 suppresses the voltage fluctuation (data component) of the electric signal supplied from the rectifier circuit 6 and stabilizes the voltage, and then supplies the DC signal to the sequencer 10 as DC power. As a result, voltage fluctuations caused by, for example, a movement of the position of the IC card 1 and voltage fluctuations caused by a change in power consumption in the IC card 1 which cause a malfunction of the sequencer 10 or the like are suppressed.
[0036]
The HPF 8 includes a capacitor 16 and a resistor 17, extracts a high-frequency component of the electric signal supplied from the rectifier 6, and outputs the extracted high-frequency component to the demodulator 9.
[0037]
The demodulation circuit 9 is connected to the other end of the capacitor 16 of the HPF 8 and one end of the resistor 17. The demodulation circuit 9 demodulates a high-frequency component signal input from the HPF 8 and outputs the signal to the sequencer 10.
[0038]
The sequencer 10 has a ROM (Read Only Memory) and a RAM (Random Access Memory) therein, and is connected to the demodulation circuit 9 described above. The sequencer 10 stores a signal (command) input from the demodulation circuit 9 in a RAM, analyzes the signal according to a program stored in the ROM, and stores the signal in a memory 11 as necessary based on the analyzed result. The stored data is read, or the data supplied from the demodulation circuit 9 is written to the memory 11. The sequencer 10 generates a response signal and supplies it to the modulation circuit 12 in order to return a response corresponding to the command.
[0039]
The memory 11 is a non-volatile memory such as an EEPROM (Electrically Erasable Programmable Read-Only Memory) that does not require power to hold data, and is connected to the above-described sequencer 10. The memory 11 stores data supplied from the demodulation circuit 9 based on the analysis result of the sequencer 10.
[0040]
The modulation circuit 12 is composed of a series circuit of an impedance 18 and an FET (Field Effect Transistor) 19, and one end of the impedance 18 is connected to the cathode terminal of the diode 13 of the rectifier circuit 6 described above. Is connected to the drain terminal of the FET 19, the source terminal of the FET 19 is connected to the ground point, and the gate terminal of the FET 19 is connected to the sequencer 10. The modulation circuit 12 is connected in parallel with the loop coil 4 constituting the above-described resonance circuit, performs a switching operation of the FET 19 in response to a signal from the sequencer 10, and varies the load of the impedance 18 on the loop coil 4. That is, a so-called additional modulation method is adopted.
[0041]
On the other hand, the R / W 50 includes a control circuit 51 for controlling data to be transmitted and received, a modulation circuit 52 and a demodulation circuit 53 for modulating and demodulating data, and a loop antenna 54 for transmitting and receiving data in combination with an electromagnetic field. And is configured.
[0042]
The control circuit 51 generates control signals for various controls in accordance with, for example, an external command or a built-in program, controls the modulation circuit 52 and the demodulation circuit 53, and generates transmission data corresponding to the command. 52. Further, the control circuit 51 generates reproduction data based on response data from the demodulation circuit 53 and outputs the reproduction data to the outside.
[0043]
In the modulation circuit 52, the transmitter modulates the transmission data input from the control circuit 51, and supplies the modulated signal to the loop antenna 54.
[0044]
The demodulation circuit 53 demodulates the modulated wave from the loop antenna 54 and supplies the demodulated data to the control circuit 51.
[0045]
The loop antenna 54 is composed of a loop coil in which a conductive wire is wound in a planar shape, radiates an electromagnetic field corresponding to the modulated wave supplied from the modulation circuit 52, and detects a load variation of the loop coil 4 on the IC card 1 side. . Note that a resonance capacitor may be connected to the loop antenna 54 in parallel or in series depending on the R / W 50 antenna driving circuit system.
[0046]
In the RFID system configured as described above, when writing of predetermined data is instructed to the ID card 1, the control circuit 51 of the R / W 50 generates a command signal for writing based on the command. At the same time, transmission data (write data) corresponding to the command is generated and supplied to the modulation circuit 52. The modulation circuit 52 modulates the amplitude of the oscillation signal based on the input signal and supplies the modulated signal to the loop antenna 54. The loop antenna 54 emits an electromagnetic wave corresponding to the input modulation signal.
[0047]
Here, the resonance frequency of the resonance circuit including the loop coil 4 and the capacitor 5 of the IC card 1 is set to a value corresponding to the oscillation frequency (carrier frequency) from the R / W 50, for example, 13.56 MHz. Therefore, the resonance circuit receives the radiated electromagnetic field by a resonance operation, converts the received electromagnetic field into an electric signal, and supplies the electric signal to the IC 3. The converted electric signal is input to a rectifier circuit 6, rectified and smoothed by the rectifier circuit 6, and then supplied to a regulator 7. Then, the regulator 7 suppresses voltage fluctuations (data components) of the electric signal supplied from the rectifier circuit 6 and stabilizes the voltage, and then supplies the electric power to the sequencer 10 as DC power.
[0048]
The signal rectified and smoothed by the rectification circuit 6 is supplied to the HPF 8 via the modulation circuit 12, and after the high frequency component is extracted, is supplied to the demodulation circuit 9. The demodulation circuit 9 demodulates the input high frequency component signal and supplies it to the sequencer 10. The sequencer 10 stores the signal (command) input from the demodulation circuit 9 in the RAM, analyzes the signal according to a program stored in the ROM, and supplies the signal to the memory 11 from the demodulation circuit 9 based on the analyzed result. Write the written write data.
[0049]
On the other hand, when the signal (command) input from the demodulation circuit 9 is a read command, the sequencer 10 reads read data corresponding to the command from the memory 11. In the sequencer 10, the FET 19 of the modulation circuit 12 performs a switching operation in accordance with the read data. That is, in the modulation circuit 12, when the FET 19 is turned on, the loop coil 4 is connected in parallel to the impedance 18, and when the FET 19 is turned off, the parallel connection between the impedance 18 and the loop coil 4 is released. As a result, the impedance of the loop antenna 54 of the R / W 50 magnetically coupled to the loop antenna 2 of the IC card 1 changes in accordance with the read data. Therefore, the terminal voltage of the loop antenna 54 changes in accordance with the change in the impedance, and the R / W 50 can receive the read data by the demodulation circuit 53 demodulating the change.
[0050]
As described above, communication is performed between the IC card 1 and the R / W 50, and writing and reading of data to and from the IC card 1 by the R / W 50 are performed in a non-contact manner.
[0051]
By the way, as the loop antenna 54 on the R / W 50 side, an antenna device 80 configured as shown in FIG. 8 was used. The antenna device 80 includes a loop coil 81 for inductively coupling an electromagnetic field, and a magnetic sheet 82 disposed opposite to a main surface of the loop coil 81 opposite to the main surface facing the IC card 1. have.
[0052]
The loop coil 81 is formed by, for example, etching a flexible insulating film such as polyimide or mica, or a conductive metal foil film such as electrolytic copper formed on both surfaces of the substrate 83. The method for producing the loop coil 81 is not limited to the above-described example. For example, a conductor pattern that becomes the loop coil 81 may be printed using a conductor paste such as a silver paste, or the substrate may be formed by sputtering a metal target. A conductor pattern serving as the loop coil 81 may be formed thereon.
[0053]
The loop coil 81 has an asymmetric shape in which the spacing and the line width between the windings facing each other across the center thereof are different in one direction. That is, the loop coil 81 has, in one direction (the vertical direction indicated by the arrow Z in FIG. 8), a lower side portion 81a in which the interval and the line width between the respective windings are reduced, and the interval and the line width between the respective windings. Has an upper side 81b that becomes wider.
[0054]
On the other hand, the magnetic sheet 82 is formed in a rectangular shape larger than the loop coil 81 so that the loop coil 81 fits within the main surface. The antenna device 80 has a structure in which a magnetic sheet 82 is attached to the surface of the loop coil 81 opposite to the surface facing the IC card 1.
[0055]
In this case, the magnetic field distribution of the antenna device 80 in one direction indicated by the arrow Z in FIG. It will be. That is, the magnetic field distribution by the antenna device 80 is asymmetric, unlike the symmetric magnetic field distribution shown in FIG.
[0056]
The antenna device 80 according to the present invention extends the communicable range between the IC card 1 and the R / W 50 by making the loop coil 81 asymmetrical and controlling the radiation magnetic field distribution by the loop coil 81. In both cases, it is possible to shift the communicable position in one direction. In the antenna device 80, the size of the loop coil 81 can be made smaller than that of the loop coil 4 on the IC card 1 side, so that the size can be further reduced.
[0057]
The antenna device 80 according to the present invention is configured such that the magnetic sheet 82 is disposed on the surface of the loop coil 81 opposite to the surface facing the IC card 1 so that the surface of the loop coil 81 facing the IC card 1 is disposed. Can be emphasized only. Therefore, the antenna device 80 can further expand the communicable range between the IC card 1 and the R / W 50 by increasing the magnetic field strength.
[0058]
The loop antenna 54 used in the above-described R / W 50 may use an antenna device 90 configured as shown in FIG.
[0059]
The antenna device 90 shown in FIG. 10 includes a loop coil 91 for inductively coupling an electromagnetic field, and a magnetic sheet 92 that is superimposed so as to penetrate the center of the loop coil 91.
[0060]
The loop coil 91 is formed by, for example, etching a flexible insulating film such as polyimide or mica, or a conductive metal foil film such as electrolytic copper formed on both surfaces of the substrate 93. The method for producing the loop coil 91 is not limited to the above-described example. For example, a conductor pattern that becomes the loop coil 91 may be printed using a conductor paste such as a silver paste, or the substrate may be formed by sputtering a metal target. A conductor pattern serving as the loop coil 91 may be formed thereon.
[0061]
The loop coil 91 has an asymmetric shape in which the spacing and the line width between the windings facing each other across the center portion are different in one direction. That is, in one direction (the vertical direction indicated by the arrow Z in FIG. 10), the loop coil 91 has a lower side portion 91a in which the interval and the line width between the windings are narrower, and the interval and the line width between the respective windings are smaller. It has an upper side portion 91b that becomes wider. In the center of the loop coil 91, a through hole 94 for allowing the magnetic sheet 92 to pass therethrough is provided.
[0062]
On the other hand, the magnetic sheet 92 has, along one direction of the loop coil 91, a rectangular wide portion 92 a that is wider than the outermost width of the winding forming the loop coil 91, It has a rectangular narrow portion 92b that is narrower than the innermost width of the winding of the loop coil 91 extending downward from the center of the lower end. That is, in the magnetic material sheet 92, the wide portion 92a has a rectangular shape larger than the loop coil 91 so that the upper side portion 91b of the loop coil 91 fits in the plane. On the other hand, the narrow portion 92b has a width sufficient to penetrate the through hole 94 of the loop coil 91, and is formed by the loop coil 91 so that the lower side portion 91a of the loop coil 91 fits within the plane. Also have a small rectangular shape.
[0063]
In the antenna device 90, the narrow portion of the magnetic sheet 92 is formed in the through hole 94 of the loop coil 91 from the surface opposite to the surface facing the IC card 1 toward the surface facing the IC card 1. The magnetic sheet 92 has a structure in which the magnetic sheet 92 is adhered to the loop coil 91 along one direction in a state where 92b is penetrated. Accordingly, in the magnetic sheet 92, in the lower side portion 91 a where the interval between the windings of the loop coil 91 is narrow, one surface side of the narrow portion 92 b faces the surface of the loop coil 91 facing the IC card 1, In the upper side portion 91b where the interval between the windings of the coil 91 is widened, the other surface side of the wide portion 92a is arranged to face the surface of the loop coil 91 opposite to the main surface facing the IC card 1.
[0064]
In this case, the magnetic field distribution in one direction indicated by arrow Z in FIG. 10 formed by the antenna device 90 is emphasized in the upper side portion 91b where the winding interval and the line width of the loop coil 91 are wide as shown in FIG. Asymmetrical one.
[0065]
Therefore, the antenna device 90 increases the communicable range between the IC card 1 and the R / W 50 by controlling the radiated magnetic field distribution by the loop coil 91 by forming the loop coil 91 in an asymmetric shape. It is possible to shift possible positions in one direction. In the antenna device 90, the size of the loop coil 91 can be made smaller than that of the loop coil 4 on the IC card 1 side, so that the size can be further reduced.
[0066]
In this antenna device 90, in a lower side portion 91 a where a winding interval of the loop coil 91 is narrow, a narrow portion 92 b of the magnetic sheet 92 faces a surface of the loop coil 91 facing the IC card 1. Since the wide portion 92a of the magnetic sheet 92 is disposed on the opposite side of the surface of the loop coil 91 opposite to the IC card 1 in the upper side portion 91b where the winding interval is widened, the loop coil Of the surface 91 facing the IC card 1, only the magnetic field distribution of the upper side 91b where the winding interval and the line width of the loop coil 91 are increased can be emphasized. In addition, the antenna device 90 increases the magnetic field strength of the upper side portion 91b where the winding interval and the line width of the loop coil 91 are widened, so that the communicable range between the IC card 1 and the R / W 50 is increased in one place. It can be greatly expanded.
[0067]
The above-described antenna devices 80 and 90 have an effective relative magnetic permeability μ ′ of 20 or more at the communication frequency in the in-plane direction of the magnetic sheets 82 and 92, and have the saturation magnetization Ms and the thickness t of the magnetic sheets 82 and 92. By setting the product Ms · t to 6 emu / cm 2 or more, the communicable range between the IC card 1 and the R / W 50 can be expanded.
[0068]
Specifically, when the relationship between the effective relative magnetic permeability μ ′ of the magnetic sheets 82 and 92 at the communication frequency and the communication range was examined, measurement results as shown in FIG. 12 were obtained. That is, in order to widen the communicable range of the antenna devices 80 and 90, the relative magnetic permeability μ ′ of the magnetic sheets 82 and 92 is preferably set to 20 or more, more preferably, the magnetic sheets 82 and 92. By setting the relative permeability μ ′ to 30 or more, the communicable range between the IC card 1 and the R / W 50 can be further expanded.
[0069]
When the relationship between the product Ms · t of the saturation magnetization Ms and the thickness t of the magnetic sheets 82 and 92 and the communication distance was examined, measurement results as shown in FIG. 13 were obtained. In order to extend the communication distance between the antenna devices 80 and 90, the product Ms · t of the saturation magnetization Ms and the thickness t of the magnetic sheets 82 and 92 is preferably 6 emu / cm 2 or more, and more preferably 10 emu / cm 2. It is preferable to make the above. The magnetic sheets 82 and 92 preferably have a holding force Hc of 10 Oe or less.
[0070]
The antenna devices 80 and 90 described above have a relative magnetic permeability μ ′ of the magnetic sheets 82 and 92 and a product Ms · of a saturation magnetization Ms and a thickness t of the magnetic sheets 82 and 92 according to a required communication range. t, and by optimizing the relative magnetic permeability μ ′ of these magnetic sheets 82 and 92 and the product Ms · t of the saturation magnetization Ms and the thickness t, the IC card 1 and the reader It is possible to widen the communicable range with the writer 50.
[0071]
In these antenna devices 80 and 90, the size of the loop coils 81 and 91 can be made smaller than that of the loop coil 4 on the IC card 1 side by improving the communication performance. The thickness of the entire electronic device such as R / W using such antenna devices 80 and 90 can be reduced to 1 mm or less, and further miniaturization and thinning can be achieved.
[0072]
Note that the above-described antenna devices 80 and 90 are not limited to those in which the intervals and the line widths between the windings of the loop coils 81 and 91 are simultaneously different. For example, only the intervals between the windings of the loop coils 81 and 91 are limited. It may be different. Further, one direction in which the loop coils 81 and 91 are asymmetrically shaped can be set to any direction in which the distribution of the radiated magnetic field should be widened. For example, the loop coils 81 and 91 may have an asymmetric shape in which the intervals and line widths between the windings of the loop coils 81 and 91 are different in the direction orthogonal to the Z direction. An asymmetric shape in which the distance between the windings 81 and 91 and the line width are different may be used.
[0073]
As described above, the antenna devices 80 and 90 described above can control the radiated magnetic field distribution of the loop coils 81 and 91 according to the direction in which the loop coils 81 and 91 are asymmetrical. It is possible to arbitrarily adjust the read / write position of / W50.
[0074]
Next, the antenna device (hereinafter, referred to as a planar asymmetric loop antenna) 80 shown in FIG. 8 described above, another antenna device (hereinafter, referred to as a three-dimensional asymmetric loop antenna) 90 shown in FIG. 10, and FIG. A conventional antenna device (hereinafter, referred to as a plane symmetric loop antenna) 200 shown in FIG. 14 is disposed in a case formed using a synthetic resin shown in FIG. 14 and a case formed using a metal shown in FIG. The comparison of the communication performance with the case where it was placed on the body was performed.
[0075]
Note that the conventional antenna device 200 used for comparison here also has a configuration in which the magnetic material sheet is disposed on the surface opposite to the surface facing the IC card.
[0076]
FIGS. 14 and 15 are characteristic diagrams showing the card position dependence of the current intensity induced in the IC card by each of the loop antennas 80, 90, and 200 disposed on the R / W side. 0 indicates the center position of each of the loop antennas 80, 90, and 200 on the R / W side, and the positive direction indicates the direction in which the IC card goes outward from the origin 0. On the other hand, the vertical axis indicates the induced current intensity generated by the magnetic field of each of the R / W loop antennas 80, 90, and 200 in the IC card side loop antenna by electromagnetic induction. Is an area where communication is possible. 14 and 15, a thin line A indicates the characteristics of the planar symmetric loop antenna 200, a medium thick line B indicates the characteristics of the planar asymmetric loop antenna 80, and a thick line C indicates the three-dimensional asymmetric loop antenna 90. The characteristics of
[0077]
When each of the loop antennas 80, 90, and 200 is used for a synthetic resin case, the conventional plane-symmetrical loop antenna 200 has two communicable areas S1 'and S2' as shown in FIG. It can be seen that the communication range has been narrowed. On the other hand, in the planar asymmetric loop antenna 80 of the present invention, as shown in FIG. 14B, although two communicable regions S1 and S2 are formed, the communicable range of the region S1 is greatly expanded. You can see that it is. Further, in the three-dimensional asymmetric loop antenna 90 of the present invention, as shown in C in FIG. 14, a communicable area S is formed only at one place from the center, and the communicable range is the largest as compared with the others. You can see that it is. The reason that the communicable region S is formed only at one position is that a single radiating magnetic field is formed as shown in the magnetic field distribution of FIG. 11 by adopting a three-dimensional asymmetric loop antenna structure. is there. Note that FIG. 9 illustrates an asymmetric phase radiation magnetic field.
[0078]
On the other hand, when each of the loop antennas 80, 90, and 200 is used in a metal housing, any of the loop antennas 80, 90, and 200 is affected by the metal housing as shown in FIG. Although the communicable range is narrower than when applied to a synthetic resin housing, the planar asymmetric loop antenna 80 and the three-dimensional asymmetric loop of the present invention are compared with the conventional planar symmetric loop antenna 200. It can be seen that the induced current of the antenna 90 is smaller and the influence of the material of the housing is smaller.
[0079]
From the above, the planar asymmetric loop antenna 80 and the three-dimensional asymmetric loop antenna 90 can improve their communication performance by continuously expanding the communicable areas S1 and S outward from the origin 0. is there. In particular, in the three-dimensional asymmetric loop antenna 90, since the communicable region S can be greatly expanded at one place, the usability is good and the impedance can be reduced as compared with the planar asymmetric loop antenna 80. This is advantageous for low power consumption.
[0080]
The planar asymmetric loop antenna 80 and the three-dimensional asymmetric loop antenna 90 can reduce the influence of the properties of the material forming the housing, and can communicate with the conventional planar symmetric loop antenna 200 in a communication range. It is possible to spread.
[0081]
Next, for each of the loop antennas 80, 90, and 200 described above, a comparison of the communication performance between the case where the magnetic sheet is not arranged on the surface opposite to the surface facing the IC card and the case where the magnetic sheet is arranged Was done. The results are shown in FIGS. 16 and 17 are characteristic diagrams showing the card position dependency of the current intensity induced in the IC card by each of the loop antennas 80, 90, and 200 arranged on the R / W side. The origin 0 on the horizontal axis is , R / W side, the center position of each loop antenna 80, 90, 200, and the positive direction indicates the direction in which the IC card is directed outward from the origin 0. On the other hand, the vertical axis indicates the induced current intensity generated by the magnetic field of each of the R / W-side loop antennas 80, 90, and 200 in the IC card-side loop antenna by electromagnetic induction. FIG. 16 shows the characteristics when the magnetic sheet is arranged, and FIG. 17 shows the characteristics when the magnetic sheet is not arranged. 16 and 17, a thin line A indicates the characteristic of the planar symmetric loop antenna 200, a medium thick line B indicates the characteristic of the planar asymmetric loop antenna 80, and a thick line C indicates the characteristic of the three-dimensional asymmetric loop antenna 90. Is shown.
[0082]
As shown in FIGS. 16 and 17, in each of the loop antennas 80, 90, and 200, the magnetic field intensity is stronger when the magnetic sheet is disposed than when no magnetic sheet is disposed, and as a result, It can be seen that the intensity of the induced current can be increased. By arranging the magnetic sheet on the main surface of the loop antenna opposite to the main surface facing the IC card, the induced current of the loop antenna on the IC card side is increased by increasing the magnetic field strength. , R / W is very effective in expanding the communicable range and reducing power consumption.
[0083]
Next, an example in which the above-described RFID system is applied to a communication terminal device 70 as shown in FIG. 18 will be described. This communication terminal device 70 uses the above-described three-dimensional asymmetric loop antenna 90 as the loop antenna 54 for the R / W 50.
[0084]
The communication terminal device 70 is a small electronic device called a PDA (Personal Digital Assistants) that can be carried by a user, and has a structure in which, for example, an information communication function, a storage function, a camera function, and the like are integrated in one module. are doing.
[0085]
The communication terminal device 70 has a main body 71 and a panel 72, and the panel 72 is attached to the main body 71 via a hinge mechanism 73 so as to be openable and closable. The main unit 71 is provided with an input unit 74 including operation buttons and the like for performing various operations. Below the input unit 74, the above-described three-dimensional asymmetric loop antenna 90 of the R / W 50 is disposed. ing.
[0086]
A microcomputer (CPU) that controls each unit is provided inside the main body 71. On the other hand, a display unit 75 including a liquid crystal display panel is provided in the panel unit 72, and the operation state of the input unit 74, data read from the IC card 1 by the R / W 50, and the like are controlled under the control of the CPU. Can be displayed. The hinge mechanism 73 has a CCD camera 76 mounted thereon, and the input section 74 can be operated to display an image captured by the CCD camera 76 on the display section 75.
[0087]
As shown in FIG. 19, the communication terminal device 70 has a main body 71 using a housing 77 formed of a metal such as a magnesium (Mg) alloy in order to secure rigidity in a case where the communication terminal device 70 is small, lightweight, and thin. Make up. A three-dimensional asymmetric loop antenna 90 is arranged in the metal casing 77. The antenna 90 is arranged to be housed in an antenna housing recess 77 a formed inside the housing 77. The antenna 90 accommodated in the antenna accommodating recess 77a is covered with a resin member 78 such as polycarbonate as a protective material to prevent the antenna 90 from falling off. The casing 77 is not limited to such a metallic one, and may be made of a non-metallic material such as a highly rigid synthetic resin.
[0088]
Here, the three-dimensional asymmetric loop antenna 90 is arranged such that the one direction of the loop coil 91 corresponds to the scanning direction of the IC card 1. The IC card 1 is scanned from the side opposite to the input unit 74 of the communication terminal device 70, that is, from the lower side 91a where the winding interval and the line width of the loop coil 91 of the loop antenna 90 are reduced.
[0089]
In this case, as shown in FIG. 20, the magnetic field distribution by the three-dimensional asymmetric loop antenna 90 is emphasized at the upper side portion 91b where the winding interval and the line width of the loop coil 91 are widened. The communicable range S between the IC card and the R / W 50 can be greatly increased at one location by increasing the magnetic field strength of the upper side portion 91b where the line interval and line width are widened.
[0090]
Therefore, in this communication terminal device 70, the communicable range between the IC card 1 and the R / W 50 can be expanded, and even when the IC card 1 is scanned from the side opposite to the input unit 74, the three-dimensional It is possible to appropriately write and read data to and from the IC card 1 irrespective of the installation location of the asymmetric loop antenna 90.
[0091]
In the communication terminal device 70, even when the housing 77 forming the main body 71 is formed of metal, the communicable range between the IC card 1 and the R / W 50 is narrowed by arranging the three-dimensional asymmetric loop antenna 90. It is possible to suppress that.
[0092]
Further, since the communication terminal device 70 can make the loop antenna 90 on the R / W 50 side smaller than the loop antenna 2 on the IC card 1 side, it is possible to further reduce the size and power consumption of this device. It is.
[0093]
Next, an example of a method for manufacturing the three-dimensional asymmetric loop antenna 90 mounted on the communication terminal device 70 will be described.
[0094]
The three-dimensional asymmetric loop antenna 90 is manufactured according to the procedure shown in the flowchart shown in FIG.
[0095]
In order to produce the three-dimensional asymmetric loop antenna 90, first, a magnetic sheet 92 is produced. When manufacturing the magnetic sheet 92, first, in step S1, a magnetic paint in which a magnetic powder, a solvent, and an additive are mixed in a binder made of a rubber-based resin is manufactured. Here, an Fe-based magnetic material containing 96% by weight of Fe, 3% by weight of Cr, 0.3% by weight of Co, and other magnetic materials was used as the magnetic powder.
[0096]
Thereafter, in step S2, the magnetic paint is filtered to produce a magnetic paint in which the magnetic powder having a predetermined particle size or more has been removed from the binder.
[0097]
Next, in step S3, the extruder shown in FIG. 22 is used to extrude the magnetic paint 96 stored in the liquid reservoir 95 from between the pair of rollers 97a and 97b, while elongating the magnetic paint 96 to a predetermined thickness. Is manufactured.
[0098]
Next, in step S4, the long magnetic material sheet 92 is dried, and the binder is removed from the magnetic material sheet 92.
[0099]
Next, in step S5, the adhesive 99 is applied to one surface of the magnetic sheet 92a while sandwiching the band-shaped magnetic sheet 92 between the pair of rollers 98a and 98b using the application device shown in FIG. I do.
[0100]
Next, in step S6, the band-shaped magnetic sheet 92 is stamped and pressed into a predetermined shape.
[0101]
As described above, the magnetic sheet 92 as shown in FIGS. 18A and 18B is manufactured.
[0102]
Next, as shown in FIG. 24, the above-described loop coil 91 is prepared. As described above, the loop coil 91 is formed by etching a flexible insulating film such as polyimide or mica or a conductive metal foil film such as electrolytic copper formed on both surfaces of the substrate 93. The method for producing the loop coil 91 is not limited to the above-described example. For example, a conductor pattern that becomes the loop coil 91 may be printed using a conductor paste such as a silver paste, or the substrate may be formed by sputtering a metal target. A conductor pattern serving as the loop coil 91 may be formed thereon. In the center of the loop coil 91, a through hole 94 for allowing the magnetic sheet 92 to penetrate is formed.
[0103]
Next, as shown in FIG. 26, the narrow portion 92b of the magnetic sheet 90 is made to pass through the through hole 94 of the loop coil 91, and the loop coil 91 and the magnetic sheet 92 are pasted in one direction. Match. At this time, the surface of the magnetic sheet 92 on which the adhesive 99 is applied faces the surface of the loop coil 91 facing the IC card 1. At a lower side portion 91a where the winding interval of the loop coil 91 becomes narrow, a narrow portion 92b is attached to the main surface of the loop coil 91 facing the IC card 1. Thereby, in the upper side portion 91b where the winding interval of the loop coil 91 is widened, the wide portion 92a can be attached to the above-described antenna housing recess 77a of the communication terminal device 70.
[0104]
Through the above-described steps, the three-dimensional asymmetric loop antenna 90 can be manufactured. As described above, the three-dimensional asymmetric loop antenna 90 has a structure in which the magnetic sheet 92 is pierced in the through hole 94 of the loop antenna 91, and the magnetic sheet 92 is superimposed on the loop antenna 90 and adhered with the adhesive 99, thereby facilitating the manufacture. .
[0105]
As shown in FIG. 27, the magnetic material sheet 92 preferably has relatively soft flexibility. In this case, deformation of the lower side portion 91a and upper side portion 91b of the loop coil 91 due to deformation of the magnetic material sheet 92 can be suppressed, and the overall thickness T1 of the three-dimensional asymmetric loop antenna 90 can be reduced. On the other hand, as shown in FIG. 28, when the magnetic sheet 92 is hard, the deformation of the lower side portion 91a and the upper side portion 91b of the loop coil 91 increases, and the overall thickness of the three-dimensional asymmetric loop antenna 90 is increased. T2 becomes thick.
[0106]
By the way, as described above, a built-in antenna unit using the planar asymmetric loop antenna 80 or the three-dimensional asymmetric loop antenna 90 is provided. In an electronic device configured to transmit and receive information, for example, in a communication terminal device as described above, a case forming a device main body having a built-in antenna portion is made of a metal such as magnesium alloy, aluminum, stainless steel, or iron. If it is formed, the IC card will not operate properly when the IC card is brought close to the metal housing. That is, when a loop antenna, which is an antenna using an air-core type coil, is used for each of the communication terminal device side and the IC card side, when the casing of the communication terminal device is made of metal, it is provided on the IC card. Since the inductance of the loop antenna decreases and the resonance frequency increases, normal communication may not be performed between the communication terminal device and the IC card. The decrease in the inductance that hinders the communication function is caused by the fact that radio waves transmitted from the loop antenna of the IC cart generate eddy currents in the metal housing. In particular, in an electronic device such as a portable communication terminal device having a built-in reader / writer as described above, the size of the housing constituting the device main body cannot be increased. Cannot be made large. As a result, in order to exchange information between the portable small communication terminal device and the IC cart, the IC cart must be in close contact with or close to a metal casing, and the The effect of the housing becomes remarkable, the inductance is significantly reduced, and communication between the communication terminal device and the IC cart cannot be performed.
[0107]
Therefore, the present invention secures the strength of a housing constituting a main body of an electronic device having a communication function formed in a small and portable size, for example, while reducing the thickness and size of a communication terminal device. In addition, the present invention constitutes an electronic device capable of executing reliable communication with an IC card having a communication function.
[0108]
Hereinafter, an example in which the present invention is applied to a communication terminal device that is a small electronic device having a communication function and formed in a portable size will be described.
[0109]
The present invention can be applied to the communication terminal device 70 as shown in FIG. 18 described above, and more specifically, is applied to the communication terminal device 121 having a communication function configured as shown in FIG. Things. As shown in FIG. 29, the communication terminal device 121 includes a metal housing 122 that forms a rectangular device main body. The housing 122 is formed using a molded body of a magnesium alloy, a nonconductive aluminum plate or brass plate having good conductivity, or a metal plate such as a nonmagnetic stainless steel plate or an iron plate. A display unit 123 is provided on one surface side of the housing 122. The display unit 123 includes a liquid crystal display panel, and is provided on one side of the housing 122. The display unit 123 is configured by a liquid crystal display panel, and displays information processed by the communication terminal device 121, processing contents, and the like.
[0110]
An input unit 125 including a plurality of operation buttons 124 and the like for performing various operations is provided at a central portion on one surface side of the housing 122.
[0111]
At the end of the housing 122 opposite to the side where the display unit 123 is provided, a card mounting unit 126 on which the IC card 110 for performing information communication with the communication terminal device 121 is mounted. Is provided. The card placement unit 126 is provided on the front side of the housing 122 where the display unit 123 and the input unit 125 are provided. In the position facing the card mounting portion 126 in the housing 122, the planar asymmetric loop antenna 80 configured as shown in FIG. 8 described above or the configuration shown in FIG. The configured three-dimensional asymmetric loop antenna 90 is provided. The communication terminal device 121 shown in FIG. 29 uses the loop antenna 90 shown in FIG. 10 as a communication antenna unit. For the specific configuration of the communication antenna unit, refer to the description of each of the loop antennas 80 and 90 described above, and further detailed description will be omitted.
[0112]
Further, in the housing 122, a reader / writer (R / W) for writing and reading data to and from the IC card 110 and a control unit for controlling each unit constituting the communication terminal device 121 are provided. . The control unit displays data read from the IC card 110 by R / W on the display unit 123 based on, for example, an operation command signal input from the input unit 125.
[0113]
Here, the IC card 110 for exchanging information with the communication terminal device 121 will be described more specifically. The IC card 110 used here is formed in the same size as an identification card conforming to the JIS standard. The IC card 110 has a length L in the long side direction as shown in FIGS. ₁ Is 86 mm, and the width W in the short side direction is ₁ And the thickness D ₁ Is 0.76 mm. In a card main body 111 composed mainly of a synthetic resin constituting the IC card 110, a memory for recording information transmitted to and received from the communication terminal device 121 and a circuit unit for controlling communication are provided. IC 112 and other electronic components.
[0114]
The card body 111 is provided with an antenna unit 115 for communicating with the three-dimensional asymmetric loop antenna 90 constituting the communication antenna unit on the communication terminal device 121 side. The antenna section 115 of the IC card 110 is provided on the outer periphery of the rectangular card body 111, that is, the opposed one and other long sides 111a and 111b of the card body 111 and the opposed one and other short sides 111c and 111d. Is formed as a loop antenna by winding a conductive body in a rectangular shape along the line. That is, the antenna unit 115 provided on the IC card 110 has a rectangular shape having long sides 115a and 115b along the long sides 111a and 111b of the card body 111 and short sides 115c and 115d along the short sides 111c and 111d. It is formed as a shaped loop antenna.
[0115]
Note that, of the IC card 110 formed in a rectangular shape, one of the long sides 115a and 115b along one of the long sides 111a and 111b of the card main body 111 is brought close to the communication antenna unit to perform communication. In the case of performing such a configuration, the short sides 115c and 115d do not necessarily have to be along the other short sides 111c and 111d, and may be inclined to these short sides.
[0116]
The antenna section 115 provided on the IC card 110 may have an asymmetrical spacing and line width between the windings constituting the long sides 115a and 115b. That is, by increasing the width and interval of the winding of one long side 111a, the radiated magnetic field distribution formed by the antenna 115 is controlled, so that the communicable range with the communication terminal device 121 is further increased. It may be.
[0117]
The communication terminal device 121 according to the present invention has a card body 111 formed in a large rectangular shape as described above, and an IC card 110 provided with an antenna unit 115 along the outer periphery of the card body 111 is a housing. When approaching and opposing the card mounting portion 126 provided on the surface of the body 122, the three-dimensional asymmetric loop antenna 90 is disposed at a position where only one of the long sides 115a and 115b of the antenna portion 115 overlaps. ing.
[0118]
In addition, the card mounting portion 126 formed on the surface of the housing 122 indicates the position of the three-dimensional asymmetric loop antenna 90 arranged in the housing 122, and furthermore, the index portion 127 indicating the approach position of the IC card 110. Is provided. The indicator 127 is formed by printing on the surface of the housing 122 or provided by engraving a part of the housing 122. The indicator 127 may be constituted by not only a symbol or a figure but also a character or the like indicating a position where one of the long sides 111a and 111b of the IC card 110 is approached.
[0119]
Here, the position of the loop antenna 90 provided in the housing 122 of the communication terminal device 121 will be described more specifically. The loop antenna 90 is configured such that one of the long sides 111a and 111b of the IC card 110 is used as an indicator. As shown in FIG. 30, when approaching to correspond to 127, one of the long sides 115 a and 115 b of the antenna section 115 on the IC card 110 side protrudes from one end 122 a of the housing 122. Position. At this time, one of the other long sides 115 a and 115 b of the antenna 115 on the IC card 110 side faces the loop antenna 90.
[0120]
That is, as shown in FIG. 30, the loop antenna 90 on the communication terminal device 121 side has a width W from one end 122a of the housing 122 to the short sides 111c and 111d of the IC card 110. ₁ It is located within a smaller area.
[0121]
In the communication terminal device 121 according to the present invention, when the IC card 110 approaches one of the long sides 111a and 111b to the index portion 127 and approaches the card mounting portion 126, the IC card 110 side One of the long sides 115a, 115b of the antenna unit 115 faces the loop antenna 90, and the other long side 115a, 115b projects outside the metal housing 122.
[0122]
In the communication terminal device 121 according to the present invention, when the IC card 110 is approached to the housing 122, the long sides 115 a and 115 b not facing the metal housing 122 are formed in the antenna unit 115 on the IC card 110 side. can get. As a result, communication of information exchange between the IC card 110 and the information written to or read from the IC card 110 without being affected by the metal casing 122 is performed.
[0123]
That is, since communication between the communication terminal device 121 and the IC card 110 can be realized between the loop antenna 90 and the long sides 115a and 115b that do not face the metal housing 122 of the IC card 110, The communication can be performed while preventing a decrease in the inductance caused by the housing 122 of FIG.
[0124]
In the communication terminal device 121 according to the present invention, in order to perform more reliable communication with the IC card 110, the width W of a portion of the metal housing 122 where the loop antenna 90 is disposed is set. ₂ Is the length L of the IC card 110 in the long side direction. ₁ Desirably smaller than the width. By configuring the housing 122 in this manner, the IC card 110 is brought closer to the card mounting portion 126, and one of the long sides 115 a and 115 b of the antenna portion 115 is opposed to the loop antenna 90 so as to overlap. In this case, the short sides 115c and 115d of the antenna unit 115 can be positioned so as to protrude to the side of the housing 122, so that a decrease in inductance due to the metal housing 122 can be prevented more reliably.
[0125]
In the communication terminal device 121 according to the present invention, the IC card 110 has one of the long sides 115a and 115b of the antenna unit 115 overlapped with the loop antenna 90 and the other of the long sides 115a and 115b is made of metal. The positioning part 130 is provided on the card placement part 126 side so as to be positioned so as not to be overlaid on the housing 122 and to be close to the card placement part 126. As shown in FIG. 31, the positioning portion 130 is configured as a step portion on which one long side 111a, 111b side of one of the sides of the card placement portion 126 that is superimposed on the loop antenna 90 of the IC card 110 abuts. .
[0126]
By providing the positioning unit 130 for defining the approach position of the IC card 110 to the communication terminal device 121 in this way, the positional relationship between the antenna unit 115 on the IC card 110 side and the loop antenna 90 is accurately determined, and the antenna unit 115 Since the portion that does not overlap with the metal housing 122 can be reliably obtained, a decrease in inductance due to the metal housing 122 can be prevented more reliably.
[0127]
Further, in the communication terminal device 121 according to the present invention, the loop antenna 90 for communicating with the IC card 110 is provided at one corner of a metal housing 122 as shown in FIG. Is also good. In this case, as shown in FIG. 32, the IC card 110 is arranged so as to cover the corner of the metal housing 122 provided with the loop antenna 90. In this manner, the metal housing 122 is formed in a rectangular shape, and the loop antenna 90 is disposed at a corner of the rectangular housing 122, so that one of the long sides 115a and 115b of the antenna unit 115 is formed as a loop antenna. 90, and the IC card 110 can be disposed on the card mounting portion 126 such that the other long side portion 115a, 115b does not overlap the metal housing 122. As in the case of 121, a decrease in inductance due to the metal housing 122 is suppressed, and reliable communication becomes possible.
[0128]
Further, the IC card 110 used in the communication terminal device 121 according to the present invention is not limited to the rectangular shape as described above, and may be a circular shape as shown in FIG. The IC card 110 may include an annular antenna section 145 in which a conductive wire is wound along the outer peripheral edge of the disk-shaped card body 141. Also in this case, when the circular IC card 110 is brought close to the metal housing 122, only a part of the annular antenna portion 145 overlaps, and the loop antenna 90 provided in the communication terminal device 121 overlaps the other. The portion is located outside the metal casing 122 and is provided at a position where it is not changed. This communication terminal device 121 is also provided with an indicator 127 that indicates the position of the loop antenna 90 disposed in the metal housing 122 and indicates the position at which the periphery of the IC card 110 is approached.
[0129]
Note that the present invention is not limited to the above-described embodiment described with reference to the drawings, and various changes, substitutions, or equivalents can be made without departing from the spirit of the present invention. it can.
[0130]
【The invention's effect】
As described above, the electronic apparatus according to the present invention can perform communication with the IC card while suppressing the influence of the metal casing while manufacturing the casing with metal. Information written or read from the IC card can be reliably transmitted and received.
[Brief description of the drawings]
FIG. 1 is a schematic diagram showing a conventional RFID system.
FIG. 2 is a plan view showing a conventional R / W loop antenna.
FIG. 3 is a schematic diagram showing a magnetic field distribution by the conventional R / W loop antenna.
FIG. 4 is a characteristic diagram showing the performance of communication with an IC card by the conventional R / W loop antenna as an induced current characteristic.
FIG. 5 is a schematic diagram showing a magnetic field distribution when the conventional R / W loop antenna is arranged in a metal housing.
FIG. 6 is a cross-sectional view showing a case where the conventional R / W loop antenna is arranged in a resin housing.
FIG. 7 is a circuit diagram showing a configuration of an RFID system used for an electronic device according to the present invention.
FIG. 8 is a plan view showing a planar asymmetric loop antenna.
FIG. 9 is a schematic diagram showing a magnetic field distribution by the planar asymmetric loop antenna.
FIG. 10 is a plan view showing a three-dimensional asymmetric loop antenna.
FIG. 11 is a schematic diagram showing a magnetic field distribution by the stereo asymmetric loop antenna.
FIG. 12 is a characteristic diagram showing a relationship between a relative magnetic permeability of a magnetic material sheet and a communication range.
FIG. 13 is a characteristic diagram showing a relationship between Ms · t of a magnetic material sheet and a communication distance.
FIG. 14 is a characteristic diagram showing, in the case of a synthetic resin housing, the performance of communication with an IC card using a planar symmetric loop antenna, a planar asymmetric loop antenna, and a three-dimensional asymmetric loop antenna as an induced current characteristic.
FIG. 15 is a characteristic diagram showing, in the case of a metal housing, the communication performance of each of the loop antennas with an IC card as an induced current characteristic.
FIG. 16 is a characteristic diagram showing a communication performance of each loop antenna with an IC card by an induced current characteristic when a magnetic sheet is not arranged.
FIG. 17 is a characteristic diagram showing the communication performance of each of the loop antennas with the IC card in the case where a magnetic material sheet is arranged, by using an induced current characteristic.
FIG. 18 is a plan view showing a configuration of a communication terminal device.
FIG. 19 is a sectional view showing a three-dimensional asymmetric loop antenna arranged in the communication terminal device.
FIG. 20 is a schematic diagram showing a magnetic field distribution by a three-dimensional asymmetric loop antenna arranged in the communication terminal device.
FIG. 21 is a flowchart showing a manufacturing process of a magnetic sheet.
FIG. 22 is a schematic view showing an extruder.
FIG. 23 is a schematic view showing a coating device.
FIG. 24A is a plan view illustrating a magnetic sheet, and FIG. 24B is a cross-sectional view illustrating the magnetic sheet.
FIG. 25 is a plan view showing a loop coil.
FIG. 26 is a plan view showing a three-dimensional asymmetric loop antenna.
FIG. 27 is a cross-sectional view of relevant parts showing a case where a magnetic sheet is soft in a three-dimensional asymmetric loop antenna.
FIG. 28 is a cross-sectional view of relevant parts showing a case where a magnetic sheet is hard in a three-dimensional asymmetric loop antenna.
FIG. 29 is a perspective view showing a communication terminal device as an electronic apparatus to which the present invention is applied and an IC card used for the communication terminal device.
FIG. 30 is a plan view showing a state where an IC card is approached to a communication terminal device to which the present invention is applied.
FIG. 31 is a perspective view showing another example of a communication terminal device and an IC card to which the present invention is applied.
FIG. 32 is a plan view showing a state in which an IC card is approached to a communication terminal device of still another example to which the present invention is applied.
FIG. 33 is a plan view showing a state in which an IC card is approached to a communication terminal device of still another example to which the present invention is applied.
[Explanation of symbols]
Reference Signs List 80 planar asymmetric loop antenna, 90 three-dimensional asymmetric loop antenna, 110 IC card, 112 IC, 115 antenna unit, 121 communication terminal device, 122 housing, 126 card placement unit, 130 positioning unit

Claims (9)

A metal housing for storing electronic components,
A communication antenna unit for communicating with an IC card having a communication function, which is disposed in the housing and has a built-in antenna unit and a communication function;
When the IC card approaches the housing, a part of the antenna part built in the IC card overlaps a part of the communication antenna part, and the communication antenna part on the IC card side An electronic device with a communication function, wherein a part of the electronic device is disposed so as not to overlap with the housing and is provided in the housing. The communication antenna unit has a loop coil for performing inductive coupling, and a magnetic body disposed to face a main surface of the loop coil opposite to a main surface facing the IC card, 2. The communication according to claim 1, wherein the loop coil has an asymmetric shape in which a conductive wire is wound in a planar shape, and a distance between each of the wound conductive wires opposed to each other across the center is different. Electronic equipment with functions. The electronic device with a communication function according to claim 1, wherein the antenna unit provided on the IC card is a loop antenna. The housing has at least a width of a region in which the antenna unit is disposed and a part of the IC card is opposed to the width of the rectangular shape of the IC card having at least a short side and a long side. 2. The electronic device with a communication function according to claim 1, wherein the length is smaller than a length in a long side direction. The communication function-equipped device according to claim 4, wherein the communication antenna portion is arranged within an area smaller than a width of the short side of the IC card from one end of the housing. Electronics. 3. The electronic device according to claim 2, wherein the loop coil is smaller than an inductively coupled antenna portion on the IC card side. The electronic device with a communication function according to claim 1, wherein the housing is provided with an index portion that indicates a position of the communication antenna portion. 2. The electronic device with a communication function according to claim 1, wherein a positioning portion for positioning a position of the IC card facing the housing is provided in an area of the housing facing the IC card. machine. The electronic device with a communication function according to claim 1, wherein the communication antenna unit exchanges information written to or read from the IC card.

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